High Quality Content by WIKIPEDIA articles! A ternary, three-valued or trivalent logic (sometimes abbreviated 3VL) is any of several multi-valued logic systems in which there are three truth values indicating true, false and some third value. This is contrasted with the more commonly known bivalent logics (such as boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by ukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945.